The Patriots have obviously undergone a lot of changes on offense this offseason. Tom Brady’s weapons caught 401 passes last year, and 356 of them (88.8 percent) are currently unavailable to the team, either through player departures (Wes Welker, Brandon Lloyd, Aaron Hernandez, Danny Woodhead, etc.) or through injury (Rob Gronkowski).

The Patriots’ identity on offense the last two seasons revolved around their star tight ends, Gronkowski and Hernandez, but what the offense will look like this season is anyone’s guess.

“I think anybody who will tell you that they know the answer to that is lying,” NFL Network’s Mike Mayock said last week, before the Patriots traveled to Philadelphia.

Well, Mayock and several national media types had the chance to watch Brady and the Patriots face the Eagles for two days in practice last week. And while experts disagree on what they think the Patriots will look like this season, most everyone agrees that the Patriots looked fantastic in the joint practices and will still be one of the league’s elite offenses.

“I’m not sure they know what it’s ultimately going to be, but if there’s one thing that Bill Belichick and Tom Brady excel at it’s flexibility, thinking outside the box, and they’ll figure it out,” Mayock said Wednesday. “They were the top offense in the league last year, and I’d be really surprised if it was much different.”

Former Colts president Bill Polian, now with ESPN, said he expects the Patriots to highlight the running game early in the season as Brady adjusts to his new receivers. The Patriots did have the second-most rushing attempts in the league last season (523), but they also ran an NFL-record 1,191 offensive plays last year and still emphasized the pass.

“I think they’ve become much more like they used to be in their championship years, when their running game was a big staple of what they did,” Polian said. “The guy that is likely to be a breakout guy is Shane Vereen. He’s got the ability to make big plays both in the run and the pass game. I would look for him to play a larger role, and that gives them two very solid running backs that they can rely upon.”

But NFL Network’s Daniel Jeremiah, a former scout with three teams, said he saw the Patriots utilize a lot of three- and four-receiver sets during Tuesday’s practice, and expects the team to work out of that personnel grouping a lot instead of trying to plug Daniel Fells, Michael Hoomanawanui, or anyone else into the Gronkowski and Hernandez roles in the two-tight end packages.

Jeremiah said he views the Patriots’ receiving corps as the strength of the offense, particularly with Danny Amendola and Julian Edelman
working out of the slot on opposite sides.

“Those are two of your better players on offense, so why not go four wide?” he said. “They don’t have a mismatch tight end until Gronk comes back. Amendola is a vet, Edelman has been in the system, and I think you build inside out. Those are your starting points.”

Jeremiah said Vereen and Stevan Ridley can be effective running out of three- and four-wide sets, but he still expects the Patriots to be a pass-first offense.

“Just put it in Tom Brady’s lap and spread the field,” he said. “You’ve got a quarterback that can think quickly and get the ball out of his hand. That’s what it looked like to me.”

The Patriots have ranked in the top 10 in scoring in each of the last nine seasons with many different types of personnel, and most around the NFL give Brady and Belichick the benefit of the doubt that they will have the offense on top of the statistical rankings again this year.

“He will build a system that makes these guys great,” former Colts center Jeff Saturday, now with ESPN, said of Belichick. “It will be the most precise offense that New England has run in a couple of years. There’s no egos, there’s nothing to manage. This is prime time New England football.”

And most observers of last week’s practices were blown away by how good Brady looked with his new receivers — Amendola and rookies Aaron Dobson, Josh Boyce, Kenbrell Thompkins, and tight end Zach Sudfeld.

“I said on TV it was like watching Jack Nicklaus at a putt-putt golf course,” Jeremiah said of Brady.

Former longtime coach Dick Vermeil, a Philly-area resident who attended Wednesday’s practice, said the process of a quarterback getting on the same page with his new receivers “isn’t as difficult as people would like it to seem.”

And Vermeil was in awe of how good Brady, 36, looked in practice.

“Awesome. That’s all you can say,” Vermeil said. “I’ve coached against him three times when I was with the Chiefs, but to see him on the practice field and see him throw the ball like that is really spectacular. You almost don’t believe somebody can throw the ball that accurately.”

Thompkins, an undrafted rookie from Cincinnati, turned a lot of heads.

“My eyes were opened by Kenbrell Thompkins,” Mayock said.

“I was shocked by Thompkins, how he and Brady were already on the same page,” Jeremiah added. Thompkins had four catches for 23 yards from Brady in Friday night’s exhibition game, all on the Patriots’ second drive.

Sudfeld, an undrafted rookie from Nevada who is working almost exclusively with the starting offense now, was also a revelation for many outsiders. An athletic 6-foot-7-inch target, he made several acrobatic catches in practice last week.

“I know you’re going to be missing a tight end but that guy right there, he’s got all the skills you need,” said Eagles radio announcer Mike Quick, a five-time Pro Bowl receiver. “He has the basketball moves inside, he knows how to uncover. Two days in a row I’ve watched him carve up the inside of the defense.”

The Patriots are likely to change their philosophy from game to game — some weeks they may go run-heavy with big personnel, and in others they may spread the field and throw a lot. But the Patriots were the league’s No. 1 scoring offense last year (34.8 points per game), and few doubt they will be near the top of the rankings again as long as Belichick and Brady are running the show.

“They’re not going to have it all together yet, but you can see, it’s a well-oiled machine,” Quick said. “When you’ve got Tom, you’ve got a leg up on most of the competition.”

AT FIRST GLANCE

It’s time to digest some leftover tidbits

A few thoughts on the Patriots’ exhibition opener Friday night:

■ The Patriots get so few opportunities to truly work on full-contact run blocking during training camp, so it was impressive to see them march 80 yards on six running plays for a touchdown to open the game. Three plays went up the middle behind center Ryan Wendell — including Stevan Ridley’s 62-yard run to open the game — and three went behind left tackle Nate Solder, who helped rip open huge holes for Ridley and LeGarrette Blount.

Brandon Bolden, who appears to be running fifth behind Ridley, Shane Vereen, Blount, and Leon Washington, didn’t help himself with a penalty for running into the punter to give the Eagles a first down.

■ The Patriots also showed a surprising number of two and even three-tight end sets, rotating Daniel Fells, Zach Sudfeld, Jake Ballard, and Michael Hoomanawanui in with the first-team offense. Final snap counts (out of 72): Hoomanawanui 34, Sudfeld 33, Fells 32, Ballard 12.

Fells had three catches for 27 yards, Hoomanawanui lined up mostly at fullback/H-back, and Sudfeld was impressive, breaking a couple of tackles on a 22-yard catch-and-run and providing the final block to finish off Blount’s 51-yard touchdown run.

Ballard started the game and felt like he made an impact, but didn’t show up on the stat sheet.

■ Impressive to see Kenbrell Thompkins connect four times on one drive with Brady. He’s probably running ahead of Julian Edelman at this point for the No. 3 receiver behind Amendola and Aaron Dobson, and he clearly has a better connection with Brady than Dobson does.

Interesting that Dobson played the most snaps among receivers (44), followed by Josh Boyce (32), Thompkins (31), and Edelman (22). Amendola had only 12.

■ Can’t imagine how tired young defensive backs Logan Ryan, Tavon Wilson, and Duron Harmon were after the game. Ryan played 82 out of 86 defensive snaps (plus seven on special teams), Wilson played 77 (17 special teams), and Harmon played 77 (11 special teams).

Ryan and Wilson both whiffed pretty badly on Greg Salas’s touchdown catch at the start of the fourth quarter.

■ Great play by defensive line hopeful Jason Vega to chase down Dennis Dixon from behind and trip him up by the shoelaces to prevent a big run.

■ Linebacker Dane Fletcher, who missed all of 2012 with an injury and is fighting for a fifth or sixth linebacker spot, had a fantastic diving breakup on a Matt Barkley pass to Zach Ertz.

■Ryan Allen definitely had the bigger leg, punting twice for a 54.0-yard average compared to three for a 44.7 average for Zoltan Mesko.

But Allen did have a 62-yard return on one punt and had the lower net average (38 to 18).

TROUBLING TREND

Relaxed contact rules to blame for injuries?

It sure does seem like there have been a rash of significant injuries through two weeks of training camp.

The Eagles lost three players to torn ACLs, the Packers lost left tackle Bryan Bulaga for the season and receiver Jordy Nelson for 4-6 weeks with knee injuries, the Steelers lost Plaxico Burress to a potentially season-ending shoulder injury, the Chargers lost receiver Danario Alexander to an ACL tear, and several season-ending injuries happened a few weeks ago, to Broncos center Dan Koppen, Ravens tight end Dennis Pitta, and 49ers receiver Michael Crabtree.

Bill Polian, the former Colts president and current ESPN analyst, thinks it’s no coincidence, and that the injuries have to do with the lighter practice rules that were established by the new collective bargaining agreement.

When the Patriots strapped on the pads July 28, it was their first time going full contact since their loss in the AFC Championship game Jan. 20. Organized team activities were always supposed to be non-contact practices, but those rules are more vigorously followed now. Minicamps are no longer padded practices, and two-a-days during training camp are a thing of the past, although some teams do hold walkthroughs in the afternoon.

“We don’t do one-on-ones anymore in OTAs, and as a result when you come into camp and put pads on, you’re not used to doing the movements. And that can hurt to some degree,” Polian said last week. “You don’t develop conditioning by walking through. You don’t need to go full blast, but jogging would be better.”

Perhaps it is time for the NFL to seriously re-examine its rules for roster sizes and injured reserve — currently, only one player per season can return from IR; everyone else is automatically done for the season. A 30-day or 60-day disabled list, like the one in Major League Baseball, could do everyone in the league some good.

NO FUN LEAGUE

Fans, players criticize celebration crackdown

The NFL is once again taking heat from fans and media for being the “No Fun League” as it pertains to cracking down on touchdown celebrations. Game officials are making their annual visits to team training camps, and warning players that unsportsmanlike penalties for celebrations will be emphasized this season.

What constitutes an unsportsmanlike celebration? Per the league’s rulebook: “Sack dances; home run swing; incredible hulk; spiking the ball; throwing or shoving the ball; pointing; pointing the ball; verbal taunting; military salute; standing over an opponent (prolonged and with provocation); or dancing.” This year, specifically, the league is going to crack down on spinning the football.

J.J. Watt, who does a military salute after each sack (similar to the old “Mile High Salute” by the Broncos in the ’90s), is especially upset that he might draw a penalty for saluting our troops.

“I’m prepared to pay some fines,” he said last week. “I’m not going to stop respecting our military. I think it’s a bad deal.”

But league spokesman Brian McCarthy made an important distinction — officials are only supposed to throw the flag if the player specifically does the celebration directly at an opponent.

The NFL wants to cut down on taunting and anything that can lead to a fight on the field. If a player wants to celebrate a big play, just find an open patch of field first.

ETC.

Robinson looking for a place to stay

Poor Laurent Robinson. In 2011 the wide receiver had a career year, catching 11 touchdowns for Dallas and turning it into five-year, $32.5 million contract with Jacksonville last offseason.

But he suffered multiple concussions in 2012, and the Jaguars cut him after one season. Robinson, 28, is getting a lot of interest — he has visited seven teams this offseason, including a workout with the Patriots — but teams are scared of his concussion history. We hear the Patriots wanted to sign him after working him out two weeks ago, but didn’t feel comfortable enough about the concussions to sign him.

Robinson is racking up the frequent flier miles. He has visited New England, New York (Jets), San Francisco, Indianapolis, Detroit, New Orleans, and Miami, but can’t get a bite. Perhaps a team will be willing to sign him after Week 1, when his contract is no longer fully guaranteed for the season.

Winning big

Former Vikings coach Mike Tice is finding out that the post-NFL life may not be so bad.

Tice was playing the ponies on Thursday at Del Mar Surfside Race Place in Southern California, and was the only person that day to hit on the Pick 6 — picking the winner in six consecutive races. Tice turned a $128 ticket into $100,796.20.

And the name of the winning horse in the second race? Tebowing. Of course.

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter @BenVolin. Material from interviews, wire services, other beat writers, and league and team sources was used in this report.